However as a stone cold cynic I think the FIA could give Webber a 10 place grid drop. That would make Alonso a net 7th and put him on the clean side of the grid.

But Vergne was out of Q2 so Toro Rosso brought the car to FIA

"upon realizing the error, the team, under supervision of a scrutineer, brought the car back to the FIA garage." With a grid penalty the possible alternate decision for the FIA, Vergne is lucky to be able to retain his 19th grid position for tomorrow’s race.

In Vergne's case, he drove the car to the garage instead of parc ferme. I think in Webber's case, he did park the car in parc ferme and the forgotten weight check is his own weight check. In that case, Vergne's incident would be irrelevant to this. I think he could be disqualified since there is no way to know if he did the qualy on legal weight. But Red Bull may be able to argue that a human being could not have gained weight so quickly and may make a case for helmet too. So, probably a 5 place penalty.

Can someone enlighten me on this procedure ? Who is weighed ? The car or driver ? How and when ?

Both I believe. There's a minimum weight that they must adhere too throughout the weekend in order for the car to be legal. If Webber made it out of a qualifying session without being weighed, the car can't be proved to have been legal during that session.

Can someone enlighten me on this procedure ? Who is weighed ? The car or driver ? How and when ?

Both I believe. There's a minimum weight that they must adhere too throughout the weekend in order for the car to be legal. If Webber made it out of a qualifying session without being weighed, the car can't be proved to have been legal during that session.

Can someone enlighten me on this procedure ? Who is weighed ? The car or driver ? How and when ?

Drivers are weighed after they finish the qualy. If they exit in Q1, it is after Q1. If they proceed to Q3, it is after Q3. Just once.

The weight is the combined weight of car, driver and helmet.

EDIT: I am wrong on this. After looking at the regulations, only the Q3 drivers are weighed by default and all drivers may be chosen randomly during Q1 and Q2. If it is true that Webber missed it only after Q1, he may escape with a reprimand.

26.2 In the event of any breach of these provisions for the weighing of cars the stewards may drop the driver such number of grid positions as they consider appropriate or exclude him from the race.

So the question is, what would be a appropriate punishment for Webber for Q1?I don't think you'll find anyone in the world trying to argue that Webber needed to cheat to get through Q1, so I don't see it being more than a warning.

So the question is, what would be a appropriate punishment for Webber for Q1?I don't think you'll find anyone in the world trying to argue that Webber needed to cheat to get through Q1, so I don't see it being more than a warning.

Can someone enlighten me on this procedure ? Who is weighed ? The car or driver ? How and when ?

From the Sporting Regulations:

26) WEIGHING26.1 a) During the qualifying practice session cars will be weighed as follows :i) The FIA will install weighing equipment in the first pit garage (the FIA garage)which will be used for the weighing procedure.ii) Cars taking part in Q1 and Q2 will be selected at random to undergo the weighingprocedure.iii) When signalled to do so the driver will proceed directly to the FIA garage and stophis engine.iv) The car will then be weighed with driver and the result given to the driver or ateam representative in writing.v) At the end of the qualifying session all cars which took part in Q3 will be weighed.If a driver wishes to leave his car before it is weighed he must ask the technicaldelegate to weigh him in order that this weight may be added to that of the car.vi) If the car is unable to reach the FIA garage under its own power it will be placedunder the exclusive control of the marshals who will take the car to be weighed.vii) A car or driver may not leave the FIA garage without the consent of the FIAtechnical delegate.viii) If a car stops on the circuit and the driver leaves the car, he must go to the FIAgarage immediately on his return to the pit lane in order for his weight to beestablished.b) After the race every classified car will be weighed. If a driver wishes to leave his carbefore it is weighed he must ask the technical delegate to weigh him in order that thisweight may be added to that of the car.c) The relevant car may be excluded should its weight be less than that specified in Article4.1 of the Technical Regulations when weighed under a) or b) above, save where thedeficiency in weight results from the accidental loss of a component of the car.d) No substance may be added to, placed on, or removed from a car after it has beenselected for weighing or has finished the race or during the weighing procedure. (Exceptby a scrutineer when acting in his official capacity).e) No one other than scrutineers and officials may enter or remain in the FIA garagewithout the specific permission of the FIA technical delegate.26.2 In the event of any breach of these provisions for the weighing of cars the stewards may dropthe driver such number of grid positions as they consider appropriate or exclude him from the race.